Hello.

My front Tyre develops a bulge. Is this safe to drive?
Just noticed it this morning. 🙁

You need to replace your tires. A buldge is an indicator that the carcass has a tear. Since the carcass is what carries the load of the tire its best to change your tires.

Curious tho what tire you are using? Not often to see a UNECE R117 marked tires made in Malaysia unless its a new tire you got with the car from the factory.

That's what I am afraid of.

Silverstone.
This is Tyre comes with the car out of factory.
Been 2yrs 9mths, but rarely drive during covid. So all in good condition (I think? ) except for this bulge.

Sorry for the late response, thanks a lot for showing the site to me!

Yes, you should replace the tire immediately. It is not safe to drive !

Tire sealant is quite a good alternative to "repair" your tire temporarily. Good cheap alternative which effectively no downside (except for cost, but since you get it for free ) No harm having it.

Oh its not free, going to have to get a new one since old owner took it. Forgot to check about spare tyre / repair kit when inspecting the car.

Full kit around rm170.

RM 170 is worth in my opinion for the "insurance" & peace of mind.

Hey TS,

I have a few questions which I hope you can assist with.

Background: Std Saga VVT using stock Silverstone M3 175/70/13 upgraded to PS3 195/50/15.

Issues: experiencing tramlining, higher body roll (likely due to softer side walls?), car isnt as composed when breaking hard either.
Only plus points seems to be grip and rather low noise, whereas with the Silverstones it was opposite (ie: higher noise, lower grip especially in the wet but the rest were fine). What gives?

.................................

Different unrelated one: 3/4 tires had a small bulge on the side wall, barely visible with naked eye but can be felt when you run your fingers over them.

Likely kena con by tire shop on the pretext of "safety". Brought the tires for inspection since they were still under warranty, rejected claim as to them they were all fine, functional and perfectly safe to be used.

I think they were referred to as sidewall indentations or undulations, due to manufacturing process, like the welds between each end.

Your take on this?

This post has been edited by Vsmh: Sep 6 2022, 09:39 AM

Replacing high profile 70R tyres with low profile 50R should rightly be 'promoting' tramlining experience and harsher ride.

At similar tyre pressures, it should help in firmer ride reducing/controlling body roll generally.

Having said that I'm not doubting your actual driving experience or perception, more so if an alignment job was carried out during rims changes as I'd a hunch that the problem is alignment related.

I defer to TS on small sidewall bulge felt by running fingers over it and associated warranty claim in local tyre industry.

This post has been edited by zeng: Sep 6 2022, 11:05 AM

1. Unfortunately doesnt seem to be controlling body roll. Not sure whats up, grips there but doesnt seem to confer the same confidence with the lower tier tire Silverstone.

2. Alignment
Yes, at first it was an alignment thing (steering felt off, a Proton drove like a Perodua), went to other places and driving experience improved, even on wheel alignment but yeah still about the same.

Should note that the roll seems to be originating from the back which the Saga is kinda known for but it wasnt like this / as pronounced on the smaller tires.

This post has been edited by Vsmh: Sep 6 2022, 11:44 AM

It will ofc be heavier and slower due to higher contact patch plus takes more power to move the car.
I think 195 ---> 185 will be quite minimal difference.
If you really mind FC and pick up, go back to 13" and get eco tires.
Can clean TB, MAF sensor, make sure engine bay air filter changed on time / not dirty, check spark plugs condition, fuel filter condition. Air gotta pump religiously. Driving style dont be so heavy footed, if red light already just let the car cruise to it then ngam ngam green and cars moving baru tekan balik and the list goes on.
Unfortunately cant have the best of both words la in such a case, usually grip -> higher fc, quiet -> grip not as good, low rolling resistance -> grip suffer etc etc

This post has been edited by Vsmh: Sep 6 2022, 01:55 PM

Hi there, thanks for asking such an interesting question. I will try my best to put on my engineering cap to answer you.

1. Changing from Silverstone M3 175/70R13 to PS3 195/50R15
Your sidewall height is reduced about 55mm which should naturally means loosing comfort as more rubber on the sidewall helps you flex, however the biggest difference is you are using a PS3 top notch wet braking tire and it is of course way better than the carbon based Silverstone M3. In my opinion the grip you got comes from the compound upgrade while you having a deficit in comfort due to sidewall height.

2. Bulge
When talking about bulges you have to be careful what bulge you are talking about. Bulges which blow up like a balloon is extremely dangerous as this means you have some damage as air can push through that area to form a bulge. However I'd the bulge is in the opposite direction, (intended inside) this is totally fine as this is caused by overlapping of the ply during production. Structurally your tire is in tact and there is not safety issues.

Hope this helps

Just to add on to this: there are tolerances for how much indentation is allowed. Although structurally fine and safe, if noticed by the consumer, it will cause undue concerns by the end user - such as what has happened to you Vsmh. Usually these indentation falls under QC issues, and would be grounds for claims. But each manufacturers have different requirements for what is allowed and what is not, so your mileage will vary. You could try to go to a different dealer to see if they would be willing to submit a complaint on your behalf. But if your tires have already been used, don’t expect a 1-to-1 replacement.

The bold suggests that the rear alignment #s of this car is off. Bigger 15" rim size is just a camouflage imho.

In a typical Saga, the rear alignment is easily adjustable IIRC unlike rear torsion beam designs in Peroduas Vios, City etc.

This post has been edited by zeng: Sep 7 2022, 07:00 AM

Interesting to note that there are tolerances acceptable in bulge/indentations and its size externally and/or internally(?) by QC .

Care to elaborate more on the QC tolerances in question or better still, if there are online resource on said acceptable tolerances?

Well i can only give a general idea of it from my experience and to cover my butt incase i give too many details.

Imagine welding two pieces of iron together. If you put too much weld material you end up with two pieces that have a big buldge at the connecting point. If you put too little you have a joint that curves inwards on itself. And if you put just the right amount it will be almost perfect (smooth to the touch but if you zoom in closer it may still be too little or too much). The same can be said with the joining of rubber materials. And hence why there must be some QC checks to make sure its not going to be an issue - both in terms of safety and in terms of customer complaints.

To be honest I doubt you will find any online resources because these would be very company specific.

Hi TS, thank you for the response, however I think you might have gotten slightly confused here, my question on no.1 is actually not about grip or loss of comfort. More to tramlining and wobbly / squishy feel. Kindly see my original post (below for easier reference)
I have a few questions which I hope you can assist with.

Background: Std Saga VVT using stock Silverstone M3 175/70/13 upgraded to PS3 195/50/15.

Issues: experiencing tramlining, higher body roll (likely due to softer side walls?), car isnt as composed when breaking hard either.
Only plus points seems to be grip and rather low noise, whereas with the Silverstones it was opposite (ie: higher noise, lower grip especially in the wet but the rest were fine). What gives?

Some times i wonder if the tire shop knew of such things (and thus took the opportunity to sell) or they really think its a safety issue.
Id agree on tolerances. Tire shop said no warranty one lah, Perodua said have but need to deal directly with manufacturer. Manufacturer (Silverstone) has kinda shut down (and they were pushing me back to Perodua), later found out they are now made and handled by Toyo tires, they were of the opinion that it was within spec and normal. All these created a perfect storm since i travel long distance and if 3/4 of my tires had a "bulge" as the tire shop called them, i was not willing to risk a single pop on the highway @ high speeds.
Just a bit of backstory, tires were within warranty period, ran for about 20K km. Now i have 4 extra tires because of this episode.

Eh, i think saga is also using torsion beam so technically there shouldnt be anything to adjust. Not sure if VVT is the same as older models tho.

This post has been edited by Vsmh: Sep 7 2022, 08:46 PM

Yea in your case Silverstone has closed down and replaced by Toyo. Maybe the buldge we are talking about are different type of buldge - since you seem to imply that 3 of your tires that came with your car has this issue. To me that doesnt seem to be very likely. Tires going to a car manufacturer would need to pass through the tire manufacturer’s QC and then again through the car manufacturer’s receiving QC department before again another round of QC before the car leaves the car factory. So maybe thats why you arent gettng anywhere with your request.

what is the averange max speed for a new tyre to turn a corner without loosing the floor grip?